1. Field of the Invention
The present invention relates firstly to a chord progression correction apparatus which modifies a part of a series of chords in order to make it more musically appropriate, to a method of such chord progression correction, and to a computer readable storage medium storing a computer program applied to the apparatus. Secondly, it relates to an automatic composition apparatus which automatically generates a melody of a complete music with given melody generation data relating to a musically highlighted portion and a series of given chords, to a method of such automatic composition, and to a computer readable storage medium storing a computer program applied to the apparatus.
2. Description of the Related Art
It is already known, in an electronic music system, that a series of chords selected by a user from among plural series of chords prepared beforehand according to a chord progression rule, can be added to a melody performed by a user or played automatically. It has also become an established knowledge that a complete melody of music can be composed automatically by using an adequate series of chords selected from among plural series of chords, and necessary data particularly inputted for musical melody generation which corresponds to various musical elements such as musical nuance, music key, motif melody, musical structure, information of pitch (e.g., register, pitch fluctuation).
In both cases when an adequate series of chords is to be given to a melody performance or automatic melody play and when a proper melody is to be automatically composed, it is often desired to particularize a music by modifying a part of the selected chord corresponding to a special portion of musical motif or musically highlighted portion. However, if a part of such selected set of chords is too easily changed by user""s primitive preference or hasty aim to fit better to a given motif melody, the chord progression often becomes less smooth and subject to miss naturalness at the point before and after such chord connection. Additionally, it has not yet been proposed in any of prior arts to compose a music automatically in consideration of xe2x80x9cmusically highlighted portionxe2x80x9d mentioned above.
In order to deal with the aforementioned problem, it is an object of the present invention to provide a chord progression correction apparatus which generates no defect of unnaturalness at the chord connection point when a part of a series of chords is changed, to provide a chord progression correction method of the same function, and to provide a computer readable storage medium applied to the chord progression correction apparatus. It is also an object of the invention to provide an automatic composition apparatus in consideration of the xe2x80x9cmusically highlighted portionxe2x80x9d, an automatic composition method of the same function, and a computer readable storage medium storing a program applied to the automatic composition apparatus.
In order to achieve the aforesaid object, the first characteristic feature of this invention lies in an automatic chord progression correction apparatus, the apparatus comprising chord change means for changing a part of a series of given chords and chord correction means for correcting a chord adjacent to the changed part to generate a new series of chords bringing a musically natural chord connection.
The above mentioned chord correction means includes, for instance, a table memorizing conditions for a musically natural chord connection, and chord determination means for determining the chord adjacent to the changed part by referring to the table according to two chords which are positioned on the both sides of the chord adjacent to the changed part, one of the two chords being included in the changed part, and another one of the two chords being included in the series of given chords.
From another viewpoint, the first feature of the invention lies both in a chord progression correction method based on the idea corresponding to the chord progression correction apparatus and in a computer readable storage medium which stores the program of the same function.
According to the first feature of the invention, when a part of the series of given chords is changed either by user""s preference or in order to make more appropriate to a given motif melody, a new series of chords can be generated automatically to make the chord connection musically more natural by correcting a chord adjacent to the changed chord found in the series of given chord. Therefore, a musically desired chord progression can always be obtained, even if a part of a series of given chords is changed under various conditions.
The second characteristic feature of this invention lies in a chord progression correction apparatus which replaces a part of a series of given chords by a chord appropriate to a given melody, the apparatus comprising detection means for detecting a chord appropriate to the given melody and whose connection with the series of given chords is musically natural, and chord replacement means for replacing the part of the series of given chords by the detected chord.
The above mentioned chord detection means, for instance, comprises chord list up means for listing up a plurality of chords appropriate to the given melody, and chord determination means for determining one chord from among the plurality of listed up chords to bring a musically natural connection with the series of given chords.
From another standpoint, the second feature of this invention lies both in a chord progression correction method based on the idea corresponding to the chord progression correction apparatus and in a computer readable storage medium which stores the program of the same function.
According to the second feature of the invention, when a part of a series of given chords is to be replaced by a different chord which fits more favorably a given melody, an appropriate chord is detected for the given melody and its chord progression in connection with the series of given chords becomes musically natural. Then, the part of the series of given chords is replaced by the detected chord is. Therefore, in case of an automatic composition system too, when a part of a series of given chords is aimed to be replaced to fit better a given motif melody, a musically natural chord progression can be automatically obtained.
The third characteristic feature of this invention lies in an automatic composition apparatus which automatically composes a music with both given melody generation data relating to a musically highlighted portion and a series of given chords, the apparatus comprising addition means for adding the musically highlighted portion as a part of a music, and setting means for setting both the melody generation data relating to the musically highlighted portion and a part of chords corresponding to the musically highlighted portion among the series of given chords for the added musically highlighted portion.
According to the third feature of the invention, it becomes possible to compose automatically a music with full of variety by placing a given musically highlighted passage at the beginning and/or the end of a music or by using it repetitively in a music so that the music may have several outstanding portions.
Preferably, the above mentioned automatic composition apparatus further comprises chord correction means for correcting a chord set for the added musically highlighted portion to bring a musically natural connection with the series of given chords. With such additional chord correction means, the given chord progression does not give unnatural impression when a musically highlighted portion is added, which makes the automatic composition apparatus be capable of composing automatically musical pieces of high quality.
Preferably, the above mentioned automatic composition apparatus further comprises transposition data adding means for adding transposition data defining a nature of transposition to the melody generation data assigned at the added musically highlighted portion. With such transposition data adding means, the automatically composed music can have still richer highlighted passages.
From another point of view, the third feature of this invention lies both in an automatic composition method based on the idea corresponding to the automatic composition apparatus and in a computer readable storage medium which stores the program of the same function.